1. Field of the Invention
The present invention relates to a dental implement which can be retained and reciprocatingly driven by the sleeve of motor-driven, reciprocating dental tool and more particularly to a dental implement which can be formed of flat stock and adapted for use in a dental tool by means of a removable tool holder.
2. Description of the Prior Art
Presently used dental implements are complex and require many operations for their production. The lower portion of such dental implements may be flat but the upper portion required to mate with the driven sleeves of present dental handpieces must provide a generally circular configuration in cross-section.
In U.S. Pat. No. 3,967,380 issued Jul. 6, 1976 tools 7 and 27 have round solid shanks 7a and 27a to mate with tool holders 2 and 22.
U.S. Pat. No. 4,526,541 issued Jul. 2, 1985 shows a dental implement 1 formed of flat stock with a flat blade 3 and a shank or holding part 2 formed with a pair of opposed, bowed ears 2a having the form of a not completely closed cylinder.
U.S. Pat. No. 4,571,184 issued Feb. 18, 1986 shows a dental implement having a split, solid, cylindrical shank 1 and a flat spatula-like portion 2.
In U.S. Pat. No. 4,834,653 issued May 30, 1989, the solid, cylindrical shaft end portion 7 of tool 1 has a groove 8 which receives spring ring 11 to lock tool 1 in place.
Weissman U.S. Pat. No. 4,954,082 issued Sep. 4, 1990 and owned by the Applicant hereof shows, in FIGS. 10 to 13A, a file tool 104 formed of stainless steel sheet material with a flat blade portion 106 and a shank 110 formed into a complete hollow cylinder as shown by FIGS. 10 to 13 or into a complete, hollow cylinder by forming an S-pattern as shown by FIG. 13A.
Similarly, in Mr. Weissman's U.S. Pat. No. 4,976,625 issued Dec. 11, 1990 the tool 4 has a blade with a molded cylindrical sleeve-shank 100.
U.S. Pat. No. 4,984,985 issued Jan. 15, 1991 shows a dental tool with a flat blade and a solid, cylindrical shank 15 with a slot 151 therein to allow the shank to pass through a restricted bore.
In each of these prior art patents the dental implement or tool has a flat blade and a cylindrical shank to mount the implement or tool in the driven sleeve in a reciprocally driven dental hand piece. The tool can be made of round stock with the blade formed into a flattened shape by secondary operations such as forging, swagging, coining etc. Alternatively, the shank can be made of round stock and a flat blade joined to it. The shank can be made more compliant by forming a slot therein. Finally, the dental implement or tool can be made of flat stock and the shank formed into a cylindrical shape by bending the marginal edges of the shank into a complete or incomplete cylinder or forming a cylinder by bending the marginal edges in an S-shaped configuration.
Regardless of the technique employed, the dental implement or tool can only be formed by a great number of operations and because of the size of the dental implements and tools, the machines used to form them must be high precision equipment.